Hello community, I have tried to look for any SAS material about computing brier score in survival analysis but I haven't been able to find any useful material.
I request for help on how to compute brier score for cox model.
Thanks in advance
Using the introductory example for proc phreg documentation and my limited understanding of the Wikipédia page , The calculation of the Brier score should go like this:
/* The following DATA step creates the data set Rats, which contains the
variable Days (the survival time in days), the variable Status (the
censoring indicator variable: 0 if censored and 1 if not censored),
and the variable Group (the pretreatment group indicator).
*/
data Rats;
label Days ='Days from Exposure to Death';
input Days Status Group @@;
datalines;
143 1 0 164 1 0 188 1 0 188 1 0
190 1 0 192 1 0 206 1 0 209 1 0
213 1 0 216 1 0 220 1 0 227 1 0
230 1 0 234 1 0 246 1 0 265 1 0
304 1 0 216 0 0 244 0 0 142 1 1
156 1 1 163 1 1 198 1 1 205 1 1
232 1 1 232 1 1 233 1 1 233 1 1
233 1 1 233 1 1 239 1 1 240 1 1
261 1 1 280 1 1 280 1 1 296 1 1
296 1 1 323 1 1 204 0 1 344 0 1
;
proc phreg data=Rats plot=none;
model Days*Status(0)=Group;
output out=ratsSurv survival=surv;
run;
proc sql;
select
mean((status-(1-surv))**2) as BrierScore
from ratsSurv;
quit;
Using the introductory example for proc phreg documentation and my limited understanding of the Wikipédia page , The calculation of the Brier score should go like this:
/* The following DATA step creates the data set Rats, which contains the
variable Days (the survival time in days), the variable Status (the
censoring indicator variable: 0 if censored and 1 if not censored),
and the variable Group (the pretreatment group indicator).
*/
data Rats;
label Days ='Days from Exposure to Death';
input Days Status Group @@;
datalines;
143 1 0 164 1 0 188 1 0 188 1 0
190 1 0 192 1 0 206 1 0 209 1 0
213 1 0 216 1 0 220 1 0 227 1 0
230 1 0 234 1 0 246 1 0 265 1 0
304 1 0 216 0 0 244 0 0 142 1 1
156 1 1 163 1 1 198 1 1 205 1 1
232 1 1 232 1 1 233 1 1 233 1 1
233 1 1 233 1 1 239 1 1 240 1 1
261 1 1 280 1 1 280 1 1 296 1 1
296 1 1 323 1 1 204 0 1 344 0 1
;
proc phreg data=Rats plot=none;
model Days*Status(0)=Group;
output out=ratsSurv survival=surv;
run;
proc sql;
select
mean((status-(1-surv))**2) as BrierScore
from ratsSurv;
quit;
Thank you very much for the assistance,. The solution works perfectly.
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